At least three people in the world have been infected with a gonorrhoea “superbug” which is untreatable and spreads through sex.
The World Health Organization (WHO) revealed the cases as it gave details of studies into highly drug-resistant forms of the sexually-transmitted disease.
Experts warned it was “only a matter of time” before last-resort gonorrhoea antibiotics would be of no use.
Teodora Wi, a human reproduction specialist at the Geneva-based UN health agency, said: “Gonorrhoea is a very smart bug.
“Every time you introduce a new type of antibiotic to treat it, this bug develops resistance to it.”
The WHO estimates 78 million people a year get gonorrhoea – an STD contracted via the genitals, rectum and throat.
The infection, which in many cases has no symptoms on its own, can lead to pelvic inflammatory disease, ectopic pregnancy and infertility, as well as increasing the risk of getting HIV.
Wi, who gave details in a telephone briefing of two studies on gonorrhoea published in the journal PLOS Medicine, said one had documented three specific cases – one each in Japan, France and Spain – of patients with strains of gonorrhoea against which no known antibiotic is effective.
Manica Balasegaram, director of the Global Antibiotic Research and Development Partnership, said the situation was “grim” and there was a “pressing need” for new medicines.
The pipeline, however, is very thin, with only three potential new gonorrhoea drugs in development and no guarantee any will prove effective in final-stage trials, he said.
“We urgently need to seize the opportunities we have with existing drugs and candidates in the pipeline,” he told reporters.
“Any new treatment developed should be accessible to everyone who needs it, while ensuring it is used appropriately, so that drug resistance is slowed as much as possible.”